Mainz 2017 – wissenschaftliches Programm
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MO: Fachverband Molekülphysik
MO 20: Clusters III (with A)
MO 20.3: Vortrag
Freitag, 10. März 2017, 15:15–15:30, N 3
Laser initiation of the interatomic Coulombic decay process in quantum dots — •Anika Haller1, Ying-Chih Chiang2, Maximilian Menger3, Emad F. Aziz1,4, and Annika Bande1 — 1Helmholtz-Zentrum Berlin, Germany — 2The Chinese University of Hong Kong, Hong Kong — 3University of Pisa, Italy — 4Freie Universität Berlin, Germany
The interatomic Coulombic decay (ICD) has originally been predicted as ultrafast energy transfer process between atoms and molecules. Recent studies show laser-induced ICD in paired quantum dots (QD) to be possible. We investigate a system of two GaAs QDs with two same-spin electrons each bound to one of the confining potentials. After resonant excitation of one electron by a time-dependent laser the system decays via ICD - interelectron energy transfer causes excitation of the other electron into the continuum. We show the field strength dependence of ICD from weak to strong-field intensities. The Fano peak profile shapes of the photoelectron spectra give a hint on the relative importance of ICD compared to the competing direct ionization. In addition, we study the impact of the laser focus. The electron dynamics is theoretically investigated by means of the space-resolved antisymmetrized multiconfiguration time-dependent Hartree method (MCTDH). As complementary approach we developed a state-resolved representation. We find multi-photon processes to be unimportant. Further, weak pulses display the highest ICD efficiency while direct ionization becomes less dominant. Focusing the laser on the light-absorbing QD further minimizes the probability for direct ionization.